1. Field of the Invention
The invention relates to a vehicle that is able to externally charge an in-vehicle battery with electric power supplied from a device outside the vehicle.
2. Description of Related Art
As a vehicle that is able to be externally charged, there is known a vehicle having a timer charging function of carrying out external charging operation in accordance with a schedule so that an in-vehicle battery is fully charged by estimated charging completion time (next estimated riding time) set by a user.
Japanese Patent Application Publication No. 8-214412 (JP 8-214412 A) describes a technique for, in a vehicle having the timer charging function, determining external charging start time so that external charging operation is completed at estimated riding time using a voltage value of an external power supply, a preset charging current value, and the like.
In the vehicle having the timer charging function, from what viewpoint a timer charging schedule is determined when a plurality of priority time periods (time periods during which an electric rate is low) are set or when a charging prohibited time period is additionally set.
From the viewpoint of cost reduction of external charging operation, it is desirable to carry out external charging operation in the priority time periods. On the other hand, from the viewpoint of reduction in standing time in a high SOC state (state where the state of charge of the in-vehicle battery is relatively high), it is desirable to complete external charging operation in a time period later as much as possible. From the viewpoint of prevention of deterioration of a relay that is operated to temporarily stop and resume external charging operation, it is desirable to minimize the number of temporary stops of external charging operation. JP 8-214412 A does not describe anything about the timer charging scheduling that takes these viewpoints into consideration.